Angelica is your classic rags-to-riches kind of character. Yes, she's the daughter of a mayor, but her family has been dirt poor for as long as anyone can remember. Plus it takes a lot more than quick money to give someone the signs of good breeding. Her grandfather, for example, was practically considered a wild animal by his hometown. But through education and her father's wealth, Angelica has managed to transform herself into a dignified young lady.
The first thing about Angelica that strikes the people around her is her beauty: "Under the first shock of her beauty the men were incapable of noticing or analyzing its defects, which were numerous; there were to be many forever incapable of this critical appraisal" (2.68). The fact that her beauty has numerous defects suggests that her personality and smile are so awesome that they prevent people from noticing what these defects are. To back this idea, the narrator continues,
She was moving slowly, making her wide skirt rotate around her, and emanating from her whole person was the invincible calm of a woman sure of her beauty. (2.68)
In spite of all her education, Angelica still has some slip-ups where she behaves with rough manners. When she's served macaroni at the House of Salina, for example,
Angelica, the lovely Angelica, forgot her Tuscan affectations and part of her good manners and devoured her food with the appetite of her seventeen years and the vigor derived from grasping her fork halfway up the handle. (2.76)
But then again, who doesn't love a good mac n' cheese? Besides, these incidents become less common as Angelica spends more and more time around refined folks like the Salinas.